Page cut-off for inking mechanism



PAGE CUT-OFF FOR INKING MECHANISM Emory W. Worthington, Dobbs Ferry, and Patrick A. Walsh, New York, N. Y., assignors to R. Hoe & Co., Inc., New York, N. Y., a corporation of New York Application July 28, 1954, Serial No. 446,212

4 Claims. (Cl. 101-365) This invention relates to improvements in inking mechanisms for printing machines and more particularly to devices for cutting off the supply of ink to one or more pages.

In one typical form of ink pump, as shown for example in Schmidt Patent 1,348,900, a number of pistons or plungers, each pumping ink for one column, are arranged in sets for supplying page widths, all plungers being operated by a common mechanism, and any given set being cut'ofi by slidably adjusting a port plate associated therewith, so as to by-pass the ink back to the reservoir instead of directing it into conduits which supply the ink rail. The mechanism for sliding these port plates has generally required the use of a shaft or rod passing through the wall of the ink pump and reservoir,

creating an undesirable leakage condition or a good deal of extra space within the pump and reservoir housing, as viewed in plan, so as to provide external access to the page cut off mechanism, without passing an adjusting member through the housing wall at a point below the ink level. The general object of the present invention is to provide a page cut off mechanism of a compact character and which does not require any packing of a rod or shaft to prevent leakage.

A mechanism embodying the invention in a preferred form will now be described with reference to the accompanying drawing, and the features forming the invention will then be pointed out in the appended claims.

In the drawing Fig. 1 is a fragmentary vertical section through part of an ink pump embodying the invention in a preferred form. Fig. 2 is a view similar to Fig. 1 but showing the parts in another position. Fig. 3 is an enlarged section on a line 33 of Fig. 1. Fig. 4 is an enlarged section on a line 4-4 of Fig. 2 and Fig. 5 is a fragmentary side elevation.

The pump generally is of known construction such as shown for example in the Schmidt patent above referred to, and the details thereof will not be described herein, except in so far as necessary for an understanding of the present invention. The pump includes a reservoir and housing structure including side walls and a bottom 11, which form an ink reservoir and also support the pumping mechanism. That mechanism includes a plate 12 carrying the various pistons or plungers 13 and imparting to them suitable vertical reciprocal and horizontal movements. The cylinders are formed in a plate 14, which is slidable and follows the piston plungers in their horizontal movement, so as to bring them over discharge ports 15 formed in bars 16 (Fig. l). The ports 15 communicate with discharge openings 17, for dis charging the ink, and in operation also communicate with inlet or supply ports (not shown), the entire operation being conventional and well understood. The bars 16, one of which is provided for each set of plungers supplying a page width, are slidably supported in the housing bottom 11 for movement between a pumping position n tsds e s Patent 0 2,838,996 l atented June 17, 1958 2 ,(Fig. 1) and a cut-off position (Fig.2). In the latter position the ports 15 are blocked ofi, and, transverse grooves 18 in the bars 16 are brought under the plungers 13, so that ink entering the pumps is returned to the reservoir, thus cutting off the supply of ink in question. The operation as thus far described does not diifer in any substantial particular from prior practice as exemplified in the Schmidt patent mentioned above.

The improved mechanism for giving the required movements to the bars 16 comprises for each bar, a vertical shaft 20 journaled in a bore in the housing wall 10, and carrying a crank pin 21 received in a slot or groove 22 in the member 16. This forms a scotch yoke type of connection, by means of which turning the shaft 20 will move the associated bar 16 from the position of Fig. .1 to that of Fig. 2.

The reduced upper part 23 of shaft '20 is received in a bore in a top member 24 which supports the usual piston stroke adjusting mechanisms 25, and shaft 20 is located vertically by shoulder 26 engaging under the member 24. The head of each shaft 20 is formed with a hexagonal socket 29 to take an Allen or similar wrench and the reduced portion 23 is formed with two flats 30 for locating the shaft in either of the positions of Fig. 1 and Fig. 2. Adjacent each pair of shafts 20 is an elongated opening 31 in the member 24 which receives a leaf spring 32. A bore 33 in the member 24 serves to accommodate a screw 35 which holds the spring in place. Turning a shaft 20 forces back one end of the spring 32 until one of the flats comes opposite this element at which point it snaps back into place holding the shaft in adjusted position. On and off markings, as shown, are provided on an index plate 27 secured to the member 24.

As will be apparent the mechanism in the invention provides a cut-off operating mechanism which creates no possibility of leakage; which requires no increase in the dimensions of the pump; which does not involve the placing of new mechanism within the general ink reservoir space and hence creates no difficulty in cleaning, and which locates the external operating element, or top of the shaft, immediately adjacent the pump structure regulating elements, so that all adjustments are placed conveniently and accessibly.

What is claimed is:

1. In a printing machine ink pumping mechanism, having a page cut 01f member comprising a horizontally slidable ported bar movable within a housing between two positions for respectively discharging ink and bypassing it back to a reservoir, operating mechanism comprising for each such page cut-ofif bar, a rotatable vertical shaft, a pin and slot connection inside the housing, formed in the shaft and bar respectively and substantially coplanar with the upper surface of the bar, and a manually turnable end upon the said shaft extending upwardly beyond the ink level within the housing and accessible from the exterior of the housing.

2. Page cut-01f operating mechanism according to claim 1, in which the housing wall has a bore rotatably carry ing the said shafts.

3. In a printing machine ink pumping mechanism, having stroke adjusting means, a member carrying the same, and a page cut-off member comprising a horizontally slidable ported bar movable between two positions for respectively discharging ink and bypassing it back to a reservoir housing, operating mechanism comprising for each such page cut-off bar, a rotatable vertical shaft, a pin and slot connection inside the housing, formed in the shaft and bar respectively and substantially coplanar with the upper surface of the bar, and a manually turnable end upon the said shaft extending upwardly beyond References Cited in the iile of this patent UNITED STATES PATENTS Bodmer L Mar. 11, 1919 Schmidt Aug. 10, 1920 Mockus Dec. 29, 1925 

